(a) Field of the Invention
The present invention relates to an adaptive communication method and a sensor node for performing the same method. Particularly, the present invention relates to an adaptive communication method for a road environment and a sensor node for performing the same.
(b) Description of the Related Art
In general, a wireless sensor network is configured by several sink nodes and a plurality of sensor nodes. Here, the sink node represents a node where data collected through the sensor nodes are gathered, and it manages the wireless sensor network with sufficient power. Also, the sensor node collects environment monitoring information, vehicle sensing information, and pollution information through an installed sensor, and transmits them. The sensor node must be inexpensive since many sensor nodes are installed in a wireless sensor network. Accordingly, low-performance batteries, memories, and processors are used for the sensor nodes. Hence, the wireless sensor network must support low power consumption, and various method for supporting the low power consumption in the wireless sensor network have been proposed.
The sensor medium access control (SMAC) protocol is the representative low power consumption transmission method of the sensor network, and each node synchronizes the operation time with neighboring nodes. Further, each node repeatedly wakes and sleeps periodically in synchronization with the operation time.
The IEEE 802.15.4 protocol is the representative communication protocol for the wireless personal area network (WPAN), and it is generally used as the communication method for the wireless sensor network. In detail, time intervals, which are called super frames, with a predetermined length are iterated, and each super frame is configured with a beacon transmission interval, an active interval, and a sleep interval.
The power efficient and delay aware medium access control for sensor networks (PEDAMACS) protocol represents a wireless sensor network communication method targeting a safe drive support service on the road. The PEDAMACS prevents communication collisions between a plurality of sensor nodes through the time division multiple access (TDMA) method in advance, and guarantees data arrival within a defined time data to minimize data transmission failure.
The wireless sensor network is also used as an infrastructure for a telematics service such as the safe drive support service, and it must support real-time data transmission and safe data transmission for the usage. However, the actual road environment frequently generates communication errors of the sensor node because of frequent traffic. Particularly, when a vehicle is located on a sensor node, the communication errors of the sensor node steeply increase. Such generation of communication errors causes the sensor node to retransmit data and thereby increase a communication delay time and reduce communication reliability. The communication methods of the above-described wireless sensor network have been designed without considering the communication errors caused by the vehicles, and it is difficult for them to perform safe data transmission on a real road.
Therefore, a method for allowing safe communication by minimizing generation of communication errors at the sensor node caused by obstacles such as vehicles on the road is required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.